The overall objective of this research proposal is to elucidate the mechanisms used by bacteria and fungi to oxidize the carcinogenic hydrocarbons, benzo(a)pyrene, benzo(a)anthracene and 3-methylcholanthrene. The metabolites formed from these three compounds by a Beijerinckia sp. and the filamentous fungus Cunninghamella elegans will be isolated by high pressure liquid chromatography and identified by conventional chemical techniques. Enzymes catalyzing the different reactions will be isolated and purified from each organism and their mechanism of action will be determined. Enzymes to be examined include cytochrome P-450 reductase, cytochrome P-450, epoxide hydrolase, glutathione transferase and UDP-glucuronyl transferase.